Fukushima nuclear plant now stable, Japan says

Operator TEPCO has completed construction of this cover on the Unit 1 reactor at Fukushima.

(Credit: Video screenshot by Tim Hornyak/CNET)

TOKYO--The Fukushima Daiichi nuclear plant has finally been stabilized after it was crippled by a tsunami in March, the Japanese government said yesterday.

Engineers working under operator Tokyo Electric Power Company (TEPCO) have brought the plant to a state of "cold shutdown," meaning the reactors can be safely kept cool and that radiation exposure is limited to 1 millisievert per year at the site's boundary.

"We are now moving from trying to stabilize the reactors to decommissioning them," Prime Minister Yoshihiko Noda told reporters, emphasizing the importance of the achievement.

"This is a challenge to not only our nation, but also the whole of humanity. I believe there will come a day when Fukushima will be remembered as the place where our future was founded by the bravery, the commitment, and resourcefulness of all our people."

Explosions occurred at four of the six reactors when cooling systems failed. They released massive amounts of radiation into the environment, forcing the evacuation of an estimated 88,000 people from a zone roughly 150 miles north of Tokyo.

Full decommissioning of the plant could take 40 years, with removal of melted nuclear fuel from the containment vessels completed in 20 to 25 years. In the meantime, TEPCO has built a cover around the Unit 1 reactor building.Noda said the government is prepared to spend more than 1 trillion yen ($12.8 billion) to decontaminate the area around the plant. Compensation payments to those affected, meanwhile, could approach 5 trillion yen ($64.2 billion).

The catastrophe was ranked alongside Chernobyl on the International Nuclear and Radiological Event Scale in terms of its overall effects.

It has also destroyed public trust in nuclear power. Other reactors in Japan have been taken offline following scheduled maintenance, leaving only seven plants in operation nationwide. However, support for nuclear power remains strong among many politicians as well as Japan's powerful bureaucracy, which has close ties with business.

If another powerful quake hits the Fukushima plant, meanwhile, the stabilization and cleanup effort could be severely set back.